So where a bank has a risk of an unauthorized financial transaction, there are multiple options to claw that back (or to shift the risk to other parties, notably merchants).

A disclosure, though, of account information is a different case, and here the results can be damaging to the banks and their customers. One instance I'm generally aware of is an increasing number of disclosures pertaining to offshore banking, many uncovered by the the ICIJ (International Consortium of Investigative Journalists: http://www.icij.org/) and the Guardian. Again, the case involves banks, but it's rather more difficult to reverse transactions when it's your client list and balances, or communications, which have spilled.

Many revealed by insiders, as it turns out.